<h2>DESCRIPTION</h2>

<em>v.what.rast3</em> reads 3D raster value for each point in the vector and updates <b>col</b> 
column in vector attribute table by this value. The column should be type double. This module is based on 
<a href="v.what.rast.html">v.what.rast</a>.
<br>
If more points have the same category, attribute value is set to NULL.
If 3D raster values is NULL, attribute value is set to NULL.

<h2>NOTES</h2>

<h2>EXAMPLES</h2>

A) Reading values from 3D raster map at position of vector points, writing these values
   into a column of the attribute table connected to the vector map:
<br>
<div class="code"><pre>
v.what.rast3 map=pnts raster3d=plume column=concentration
</pre></div>

<p>
B) In case of a vector map without attached attribute table, first add
a new attribute table. This table is then populated with values
queried from the raster map:
<br>
<div class="code"><pre>
# create new random 3d vector points map
v.random -z output=pnts npoints=100 zmin=0  zmax=50

# add new table, link to map
v.db.addtable map=pnts column="concentration double precision"

# query raster map and upload values to vector table into specified column
g.region raster3d=plume -p
v.what.rast3 map=pnts raster3d=plume column=concentration

# verify new attribute table:
v.db.select map=pnts

# verify statistics of uploaded values:
v.univar map=pnts column=concentration type=point
</pre></div>

<h2>SEE ALSO</h2>

<em>
<a href="v.db.addtable.html">v.db.addtable</a>,
<a href="v.db.select.html">v.db.select</a>,
<a href="v.what.rast.html">v.what.rast</a>,
<a href="v.what.vect.html">v.what.vect</a>,
<a href="v.univar.html">v.univar</a>
</em>

<h2>AUTHOR</h2>
Soeren Gebbert, heavily based on v.what.rast by Radim Blazek

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